Diesel fuel can last six months to a year with proper maintenance and storage practices. If fuel can be kept clean, dry, and cool, twelve months is the average it can last. Depending on how you store your diesel, you may want to consider fuel polishing if your fuel has become contaminated before the end of its shelf life.

Diesel fuel polishing is a simple way to filter foreign debris out of fuel that has been kept in less-than-ideal storage conditions. Keeping your fuel clean from contaminants means protecting your engines and fuel systems from corrosion, decreased performance, and expensive repairs. If you notice water, particulate matter, or rust has gotten into your fuel tank, fuel polishing can help salvage as much useable fuel as possible.